Electric toaster



' July 7, 1936. G. LAVENBURG ELECTRIC TOASTER Filed April 5, 1933 3 Sheets-Sheet 1 ATTORNEY `uly 7, 1936. G, LAVENBURG 2,046,471

ELECTRIC TOASTER Filed April 5, 1953 v3 Shee'tS-SheeI 2 INVENTOR JMA/,walk

ATTORNE( vJuly 7, 1936. G. LAVENBURG ELECTRIC TOASTER Filed April 5, 1933 3 Sheets-Sheet 3 v au ko/yal @www5 any INVENTOR ATTORNEY Patented July 7, 1936 UNITED STATES PATENT OFFICE 2,046,471 ELECTRIC 'roAsTEa George Lavenburg, New York, N. Y. 5.. sa Application April 5, 1933, Serial No. 664,493

9 Claims.

This invention relates to new and useful improvements in electric toasters and particularly to toasters of the so-called automatic type in which the operation once initiated is automatically terminated upon the expiration of a predetermined period of time.

The objects of theinvention are the provision of a simple, rugged and inexpensive timing mechanism; the initiation of all operations by a single manual operation, e. g., by pulling down a single lever; means whereby the automatic timing of the toaster may be at times delayed, suspended, speeded up, or entirely replaced by manual operation without the necessity of performing any special operations; the provision of a toaster in which the bread gradually appears in view from the oven and continually moves during the toasting.

With these objects in view, I provide a timingdevice which is mechanically at all times disconnected from the toaster and which in the present embodiment of the invention consists of a motor delivering impacts at a movable member which, after traveling a` certain distance, terminates the toasting operation. In the present case, the impacts are delivered by means of a steel ball which the motor hurls against the movable member.

Y The movable member is held in its advanced position and the ball is returned to the motor by gravity.

The bread and oven are gradually and continuously moved with respect to one another, preferably by raising the bread under the control of said movable member and the toasting operation is terminated when the movable member reaches a predetermined position. Owing to this continuous motion, the bread will be evenly toasted throughout its surface and the apparatus is never subjected to sudden jars. Besides, the operator may beforethe completion of the toasting determine its suiiiciency.

The operation is initiated by a single manual operation, e. g., by pulling down a handle. This will lower the bread within the oven, advance said -member into its starting position, close the circuits of the motor and the heating elements and thus start both the toasting and timing operations.

Through the agency of said handle, the timing with the bread projecting from the oven and said circuits interrupted.

These and other features of the invention will more fully appear from the following description of a preferred embodiment thereof and the appended claims. Obviously, these details may be changed without departing from the spirit of the invention, and some of these features may be embodied in other types of toasters.

.In the drawings, Fig. 1 is a vertical cross-section of a toaster;

Fig. 2 is a top plan view with parts of the cover removed;

' Fig. 3 is an end elevation with parts of the cover removed;

Fig. 4 isa perspective view of the oven section;

Fig. 5 is a sectional view alonglines 5-5 of Fig. 2;

Fig. 6 is a sectionaliview along lines 6-6 of Fig. 5; and

Fig. 7 is a circuit diagram.

The toaster consists of an oven and an operating mechanism, the former enclosed within a casing I and the latter within a casing 2. Both casings are mounted on a common base 3 which is open below the oven, as indicated at 4, so that bread crumbs may fall through into a removable drawer 5. The top of the oven is covered by a plate 6 provided with four longitudinal slots or openings 1 in alignment with vertical oven compartments and of a size to permit free passage of a slice of bread. A slice of bread inserted through these openings will be guided between guard wires 8 suspended on both sides. of each oven compartment from squared rods 9 one end of which rests in notches |0 provided in a rail II fastened to a side wall of the casing I. The other ends of the bars 9 are supported in notches of a rail I2 mounted on a side wall I3 of the oven which separates the oven from the chamber enclosing the timing and controlling mechanism. The bars 9 are arranged in pairs, the bars of each pair being spaced from one another to hold the upper edge of a heating element composed of two notchedmica sheets I4 on which a resistance wire I5 is wound. 'Ihe -two ends of the resistance wire .terminate in metal tabs I6 at the bottom of the mica sheets I4, the metal tabs being held in connecting clips II'and I8, respectively, mounted on conductor rails I9 and 20 carried on posts 2| on the base plate 3 but insulated therefrom. Current is supplied to the rails I9 and 20 through binding posts 22. It will be noted that the bars 9with the guards 8 are removable and the .heating elements are also removably mounted in the clips so as to insure quick and easy removal and change which can be eiected simply by removing the oven top 6.

yThe guards .8 prevent the bread from coming in contact with the @rating elements, and strips like 23 dependingfrom the rail II keep the bread from sliding into contact withthe side wall .of the casing I. Each slice of .bread will rest on a bread platform 24, the bread platform having projections 25 between adjacent guard wires 8 to prevent slipping of the bread off the platform and into contact with the heating element between adjacent guard wires.

' Each bread platform 24 has an extension '26 projecting through a longitudinal slot in the separating wall I3, all the extensions 26being fas- I Atened to a crossbar 21.

In their normal position, the bread platforms are in the position indicated in dotted lines in Fig. 1. After a slice of vbread has beenV inserted within each oven compartment and is resting on its platform 24, the attendant lowers the bread entirely within the oven and starts the operation of the toaster by grasping a handle 23 and moving it from the position indicated in dotted lines in Fig. 1 into the position indicated in full lines. The handle projects through a slot in the top of the casing 2. Its forked end ,29 within the casing 2 is fastened to -the two ends of a cross piece 30. The cross piece 331s adapted to slide back and forth between the top edge of.a trough 3I and a cover plate 32 which is straddled by a bent-up portion 33 of the cross piece 3D. Fastened to the lower end of the cross piece 3|ll there is a slider 34 within the trough 3l and the two ends of the cross piece are engaged at their under side on both sides of the trough 3I by levers 35 and 36. 'Ihe ends of these levers are pivotally mounted on a shaft 31 which is encircled by a, double wound spring 38, a central tongue 33 of which bears against a post 40 mounted-on. the base plate 3. The two free ends 4I and 4Z of the spring 38 engage the levers 35 and 36 and urge them upwards against the cross piece 30.

When therefore the operator moves the handle as above stated, the cross piece 30 will depress levers 35 and 36 against the tension of spring 38.

During the forward movement of the slider 30 the bread platformsl are lowered by their own weight and by the weight of the bread slices, the positioning of the bread platforms being .con-

trolled by a at vcable 43, one end of which is attached to the upright piece 33 of the slider at 44 and the other end of which is attached to the cross bar 21 at 45 near the center thereof. The cable 43 passes over an idler pulley 46 mounted on a port 41 on the base plate 3 and on a pulley 43 mounted in a bracket 49 on the oven wall I3 above the slots 21. The'horiz'ontal positioning of the cross bar 21 and of the bread platforms is insured by a sleeve 56 fastened to each end of the cross bar 21. A post 5| fastened to the base plate 3 projects within each sleeve 5U, the sleeves being free to slide up and down on these posts. Shortly after the cross piece 21 leaves its top position a finger 52 projecting therefrom will tip a. mercury switch 53 from the position shown in dotted lines in Fig. 3 into the position shown in full lines. The mercury switch 52 is clamped in a bracket 54 which may oscillate around a shaft 55 fastened tothe separating wall I3, said bracket, 54 having a tongue 56 projecting into the path of the finger 52 on the cross bar 21.

when the mercury switch is thusv tipped it will close a circuit (Fig. 7) fromthe power line 60, through the irst three resistances I 5 in parallel, through conductors 6I, back to the other side of the power line 60. A parallel circuit is closed through the mercury switch 53, a variablev 5 resistance 62 and a motor 63, and a third parallel circuit through the last two resistances I5, a switch 64 and conductor 6I. If the switch 64 (which is suitably mounted on the outside of the casing) is closed, all the resstances I5 will be traversed by current and, depending on the -setting'of the variable resistance 62 (also suitably mounted on the outside of the casing), the motor 63 will start rotating its shaft 65 at a certain speed. The various electrical connections are la suitably established by means of a terminal block 66, mounted on the base plate 3.

'Ihe projecting shaft of the motor carries fan blades 61 to cool the compartment within the casing 2 and at its end it carries an impeller 63 2c suirlciently to permit free rotation. As indicated in Fig. 1, the trough 3I is inclined towards the 25 i impeller 68, the higher end of the trough being fastened at 63 to the upright 43 which, as shown. forms a leg of the cover plate32.

As viewed from the. motor side (Fig. 1), the shaft l65 of the electric motor rotates in a clockwise direction and therefore the impeller 68 will drive steel ball 10 towards the slider l34 (see Fig. 5). Owing to the inclined oor of the trough 3l the steel ball10 will tend to rollback into contact with the impeller 68, the ball being prevented from falling out because its diameter is larger than the separation between the impeller 63 and the end of the trough 3i. Whenever the impeller 63 delivers a blow to the ball it will drive it towards' the slide 34, the trough 3 I and its cover plate 32 serving as a guide to keep the ball moving between the impeller and the slide.

In response to each impact delivered to the slide 34 by the ball 16, the former is caused to advance towards the left (Fig. 5), the impact being sufflcient to overcome the frlctional resistance between the slide and its trough, between the levers 35, 36 and the cross piece 30-'which, as above stated, is attached to the slide, and between the cable 43 and pulleys 46 and 43. However, once this frictional resistance overcomes the force of the impact, the slide is lheld in its advanced position by the levers 35 and 36 which, under the control of spring 38, rise step by step during each advance step of the slide.

While the slide is thus driven by the ball 16 it will draw upward by means of the cable 43, the cross bar 21 and the bread platforms 24 attached thereto. 'I'he slices of bread resting on the bread platforms will therefore be continuously and gradually moved out-of the oven compartments. During the travel past the incandescent resistance wires I5, both sides .of the bread slices will be toasted, and owing to the fact that the bread moves continuously with respect to the resist- 65 ances, the'toasting will be substantially uniform throughout the surfaces of the bread slices.

finger 52 is above the tongue 56 of mercury switch bracket 54. The bread slices are now protruding through the opening 1 of the oven top 6 about moved with respect to the resistance elements,

21/2 inches and may be removed by the attendant. At the beginning of the toasting operation the lower edge of the bread is preferably below the tab I6 of the resistances, the same distance as i it is desired the bread will extend out of the casing at the end of the toasting operation.

The speed of rotation of the m'otor 63 is so timed by means of the rheotstat 62 that just sufficient time elapses between the closing and'open- -ing of the circuits by the mercury switch 53 to toast the bread slices to the desired extent. Owing to the fact that there is no physical connection between the timing element constituted by the motor and its shaft and the timed element constituted by the slider 34 and its associated equipment, and that there is no physical connection between the ball 'l0 and either the timed or timing elements, the attendant may at any time arrest, slow down, speed up, or entirely eliminate the timing operation simplyby grasping the handle 28. 'I'hrough the handle theattendant can operate the timed element at will and thus manually control the toasting operation since the impact of the ball 10 is insuicient to overcome such resistance. The attendant may, for instance, when noticing that the protruding upper edges of the bread slices are insuciently toasted, again move` the slide 34 all the way back to the right so as to permit it again being driven by the ball 10, or he may simply arrest the further elevation of the bread pieces until they are more fully toasted. Again, the attendant may push the slide 34 to the left faster than it would be driven by the ball 10, thus speeding up the toasting operation. Since, as above stated, there is no physical connection between the timing and timed elements, these operations by the attendant can be performed without the necessity of operating any clutches, shifting connections or the like and should for any reason the timing element fail to operate the toaster can be used as a manually operated device Auntil the necessary repairs can be effected.

By openingthe switch 64 the device can be used to Atoast two instead of four slices of bread. It will be obvious to those skilled in the art that numerous changes can be effected in the em` bodiment of the invention without departing from the spirit thereof. While the timing arrangement has. particular advantages in connection with toasters, it may be used for timing other operations and certain features of the toaster may be used in combination with other types of timing devices. Furthermore, while in my preferred embodim'ent the bread is gradually and continuously some of the features of my invention may be embodied in toasters in whichautomatic bread toasting is effected by different relative ments.

What is claimed is:

1. In an electrictoaster, an oven, electric heating elements therein, an electric motor,V a shaft rotated by said motor, a movable element physically spaced from said shaft, a ball adjacent said shaft and moved in response to rotation thereof, means for guiding said ball towards said movable element, means controlled by said movable element for moving bread out of said oven, and circuits for said motor and heating elements also controlled by said movable element.

2. In combination, an open-ended trough, a slider within said trough, a spring-pressed lever move- Vcommon branch for said motor and resistances, a

holding said' slider against advancement, anl electric motor having a projecting shaft of angular cross section blocking the open end of said trough but spaced therefrom to allow free rotation, a ball within said trough having a larger diameter than the spacing between said trough and shaft and moved in response to the rotation of said shaft, and a circuit for said motor controlled by said slider.

3. In combination, an inclined trough' open at its lower end and having a cover plate spaced therefrom, a slider within said trough, a cross piece carried by said slider between the trough and its cover plate. two spring-pressed levers pivoted at one end bearing against the under l side of said cross piece, a handle attached to said cross piece, an electric motor having a shaft, an impeller of angulaicross section on said shaft and blocking the open end of said trough but spaced therefrom to allow free rotation, a ball within said trough having a larger diameter than the spacing between said trough and impeller and moved in response to the rotation of said impeller, and a circuit for said motor, and a switch in said motor circuit 2 controlled by said cross piece.

4. In an electric toaster, an oven having openings, electric heating elements dividing s aid oven into compartments in alignment with said openings, a bread platform within each oven 3 compartment, moving means for said platforms outside of said oven, an inclined open-ended trough, a slider within said trough, a springpressed lever for holding said slider against displacement, an electric motor having a shaft. an 3 impeller of angular cross section on saidv shaft and blocking the open end cf said trough but spaced therefrom to allow free rotation, a ball within said trough having a larger diameter than the spacing between said trough and impeller and moved in response to the rotation of said impeller, circuits having a common branch for said motor and resistances, a variable resistance in the motor circuit, and a switch in said common branch controlled by said moving means for said platforms.

5. In lan electric toaster, an oven having openings in the top of a size to permit passage of a slice of bread, electric heatingjelements dividing said oven into vertical compartments in alignment with said openings, a bread platform within each oven compartment, extensions of each platform projecting through slots in a side wall of said oven, a bar-interconnecting said extensions outside of said oven, an inclined openended trough having a cover plate spaced there-.- from, -a slider within said trough, a cross piece carried by said slider between the trough and its cover plate, two spring-pressed levers pivoted at one end'bearing againstthe under side of said -60 switch in said common branch controlled by said bar interconnecting the platform extensions but 'only in one position thereof.

6. A toaster 'comprising electrical heating 75 means, a food support adjacent said heating means, a switch for controlling the circuit of said heating means, a handle for moving said support from a normal position to any one .of a plurality of advanced positions, and means for automatically opening said switch after the lapse of varying intervals of time depending on the advanced position to which the support has been moved, said last mentioned means including frictional means for holding said support in any advanced position and a device for overcoming said frictionalmeans.

'7. A toaster comprising an oven, electric heating means associated with said oven, a food support adapted to be moved from a normal position to any one of a plurality of advan'ced positions within said oven, and automatic means for moving said support outwardly' from said oven during the toasting operation, said last mentioned means including frictional means for holding said support in any advanced position and a. device for overcoming said frictional means.

8. In a toaster, normally inactive electric heating means, a support normally holding food near said inactive heating means, manual means for moving said support Aadjacent said heating means into any one of a plurality of advanced positions,

means operative upon the movingof thel support y out of the normal position for closing a circuit for said heating means, frictional means for holding said support in any advanced position, and automatic means including a device for overcoming said frictional means for moving said sup-y port from any advanced position back to the normal position whereupon said circuit is opened.

' 9. VA toaster comprising an oven, electric heat.- ing means associated with said oven, a food support adapted to be moved from a normal position to any one of a plurality of advanced positions within said oven, automatic means for moving said support outwardly from said oven .during the toasting operation, a mercury switch for controlling the circuit of said heating means, a

pivotal mounting for said switch, means includy ing said support for tilting said switch in one direction to close said circuit, said automatic means including a timing mechanism having a slide with two ends, a slider adapted to move along said slide, means for gradually advancing said slider to one end of said slide, and means for gradually tilting said switch in the opposite direction to open said circuit as said slider advances to said one end.

GEORGE LAVENBURG. 

